Method and apparatus for folding lengths of material

ABSTRACT

Lengths of material, such as plastic bags, fed from a bag forming machine are individually folded one or more times prepatory to packaging. Each length of material is wrapped around spaced and axially opposed vacuum pickup rollers to form a hollow cylindrical roll on said rollers. The roll is then bent in half by means of a blunt edge blade disposed with its longitudinal axis transversely related to the longitudinal axis of said hollow roll and the hollow roll is pushed in between two creasing rollers which bring both halves of the cylindrical roll together and squeeze each half into a flat creased folded portion.

3,559,983. 2/1971 -Sj0strom United States Patent my Weist I I 1111 r 3 ,--711,086 1 51 Jan.16',19 73 [s41 Memo!) PPARATUS FOR 1 FOLDING LENGTHSOF MATERIAL [76] Inventor: Herman c. Waist, 1860 Arlington Avenue, Louisville-Ky. 40206 221 Filed Sept. 1, 19711 [21]. Appl.No.:68,'631 i 521- US. c1..- ..'....'...27o/s3, 53/118, 53/120,

4 93/1 93/8, 270/61, 270/69 [51] Int. Cl. ..B65h 45/18 1581 Fielddsearch ..270/6l,69,83-.-85,

55 1 3 References Cited UNITED STATES PATENTS 3/1970 Grulich et 3| ..-...53/1 16 1/1966 Gore et al.....

3,590,697" 7/1971 Schaffron, 270/61 Primairj/ Examiner--Robe rt Michell Assistant Examiner-L. R. Oremland Attorney-William R. Price [57] ABSTRACT- Lengths of material, su'ch'as plastic bags, fed from a bag forming machine are individually folded one or more times prepa'tory to packaging. Each length of material is wrapped aroundspaced, and axially opposed vacuurn pickuprollers to form a hollowcylindrical' roll on said rollers. The roll is then bent in half by means of a blunt edge blade disposed with its lon-.

gitudinal axis transversely related to'thelongitudinal axis of said hollow roll and the hollow roll is pushedin between two creasing rollerswhich bring both .halves of the cylindrical roll together and squeeze each half into a flat creased folded portion.

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B w mi- METHOD AND APPARATUS FOR FOLDING LENGTHS OF MATERIAL FIELD OF THE INVENTION This invention relates to a new and improved machine for individual folding plastic bags or other lengths of material from a material severing device. Plastic bags, which are used to line containers, such as garbage cans, are discharged from a bag forming machine as a tube of extended length. These bags have been batch-folded by hand. This invention relates to a new and improved machine to permit mass individual folding of bags, sheets of plastic and the like for packaging.

DESCRIPTION OF THE PRIOR ART Previously, large plastic polyethylene bags have been batch-folded manually. Proposals to individually fold such bags mechanically have not been commercially successful.

SUMMARY OF THE INVENTION According to this invention, a simplified and space conserving apparatus is provided consisting of two spaced and axially opposed vacuum pickup rollers located at the discharge end of a bag forming machine. The flattened tube of a material fed from the web through the bag forming machine feeds onto the vacuum pickup rollers so that the lateral edges of the bag are engaged in gripping relation with the peripheral surfaces of the pickup rollers. The bag is then rapidly rolled or wrapped around the pickup rollers to form a large hollow cylindrical roll. This roll is bent in half by the engagement of a blunt edge blade at its midpoint which pushes the roll downwardly and bends same so that its leading edge comes into engagement with a pair of driven squeezing or creasing rollers which bring the two halves of the roll together. This flattens each half of the roll and forms creases or fold lines. The folded bag is then discharged from the creasing rollers onto a conveyor leading to a packaging station.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in perspective of the rear or feed portion of the machine.

FIGS. 2 through 4 present sequential views in perspective of the web of plastic being fed over the vacuum pickup rollers and pushed into the squeeze or creasing rollers.

FIG. 5 is a fragmentary front view in perspective, illustrating a portion of the driving mechanism for the crushing rollers and illustrating thereciprocating mechanism for the frame of the bag folding device.

FIG. 6 is a view in perspective of a fragment of the feed portion of the machine illustrating the vacuum means for the vacuum pickup rollers and the driving means for the rollers.

FIG. 7 is a sectional view, taken along lines 7--7 of FIG. 6, illustrating the communicating passage between the vacuum outlets of the vacuum pickup rollers and the suction manifold.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, the machine consists of a frame 1, made up of series of steel channels, comprising a foot portion 2, an upright portion 3, a side channel member 4 and front and rear crosspieces 5. Mounted on the front and rear crosspieces 5 is a bearing support 8 for linear bearing 11. A movable crosspiece 10 is mounted on the linear bearing 11 by means of mounting bracket 17 and depending pillow blocks 16 supports the pickup roller assembly 12, so that the entire assembly may reciprocate toward and away from the bag forming apparatus or other material severing device in timed sequence. Mounted on the movable crosspiece 10 is a mounting bracket 18 for journal 19 of shaft 20 which acts to drive the rotatable vacuum pickup rollers of the pickup assembly 12 as will be later described.

Referring now to FIG. 6, the driving means for the shaft 20 is through variable speed DC motor 22 by way of belt 23 trained over the pulley of the electric brake and clutch assembly 25 and 26. Shaft 24 controlled by the electric clutch 26 and the electric brake 25 drives belt 28 which in turn is trained over the pulley of the driven shaft 20. Vacuum pump 27 leads to vacuum hose 32 and contains vacuum cutoff valve 34 which runs to the T fitting 33 for the vacuum hose. Fitting 35 connects the T fitting 33 to the vacuum manifold 36. Vacuum manifold 36 is in communication with the hollow shaft 43 of pickup roller 44, which, in turn, is in communication with vacuum passages 40 in the pickup roller 44 which open into the peripheral vacuum outlets 45. The hollow shaft 43 is connected to the pickup rollers 44 to rotate same and is driven by driven sprocket 41 which in turn is powered by chain 42 off of the drive sprocket 40 of the driven shaft 20.

A vacuum roller guard 47 acts as a guard and a guide for the web of polyurethane or other material fed onto the vacuum rollers. As the plastic web engages the pickup rollers 44, vacuum through vacuum outlets 45 is applied to the lateral edges of the web so that the web is wrapped onto the spaced and axially opposed rollers 44 to form a large hollow cylindrical roll. A vacuum transfer groove 48 may be provided between alternate pairs of vacuum outlets 45 of the roller 44.

At the first stage of this operation, illustrated in FIG. 2, the entire assembly 12 is pushed into close proximity to the bag forming machine. As the web wraps around the rollers 44, the entire assembly moves longitudinally away from the bag forming machine, placing some tension on the web and on the roll being formed on the rollers. Thus, as the knife severs the roll from the webb on the machine, as illustrated in FIG. 4, the rollers manage to roll due to slippage of electric clutch 25 and piston rod 54 extends thereby engaging the blunt edge blade 57 with the middle of the roll of plastic, tending to bend it downwardly into engagement with the creasing rollers 68. As is illustrated, the longitudinal axis of the blunt edge blade 57 lies transversely to the longitudinal axis of the roll formed on the pick up rollers 44 but parallel to the longitudinal axes of the driven creasing rollers 68 below the pickup rollers 44 and the roll formed thereon. Thus, as the rolled up web is bent in the middle, the leading edge of the bent roll is engaged with the creasing rollers 68 the two halves of the cylindrical roll are squeezed together and each ,half of the roll is squeezed together in creasing engagement so that the entire folded roll is discharged from the driven rollers 68 in folded condition. 7

As will be appreciated, holes 46 running through the body of the roller 44 allows air to escape from the center of the hollow cylindrical roll as the blade 57 bends the roll in half.

Simultaneously therewith, vacuum from the vacuum pump 27 is cut off by means of vacuum cutoff valve 34; allowing the rolled bag to be released from the vacuum pickup roller 44.

As is best shown in FIG. 1, the air cylinder 53 is supported on the movable crosspiece 10 by means of bracket 50. The cylinder 53 contains lines 51 and 52 which cause the piston rod 54 to extend and retract respectively.

Referring now to FIG. 1 and 5, the driving mechanism and reciprocating mechanism for the driven rollers and for the bag folding apparatus 10 are shown. Motor 59, supported on bracket 60 is shown beneath front crosspiece 5. Referring to FIG. 5, the driven shaft 61 from the motor 59 drives drive sprocket 62 and driven sprockets 63 are thereby driven by belts 64 to drive the creasing rollers 68 in clockwise and counterclockwise direction respectively. Further, as

will be noted, air cylinder 76 is supported by mounting member bracket 78 on crosspiece so that the piston rod 77 is connected to the movable crosspiece member by means of mounting member 79. Thus extension of the piston rod 77 pushes the entire folding assembly 12 toward the bag forming machine while retraction of the air cylinder 76 pulls the entire apparatus away from the bag forming machine so that the bags can be folded and driven through driven rollers 68 to be deposited down slide 80 onto moving conveyor belt 82. Control Box 81 is shown in FIG. 1 on upright 111.

While many modifications will be apparent to those skilled in the art, the aforesaid description and drawings are meant to be exemplary in nature and nonlimiting .ll'l scope except as to be commensurate in scope with the appended claims.

I claim:

1. A material folding apparatus, for folding lengths of material fed from a web severing apparatus, which comprises:

A. a frame,

B. a feed portion for feeding said web onto said apparatus;

C. a pair of spaced and axially opposed pickup rollers rotatably journaled in said frame and engagable with the lateral edges of said web, each of said rollers including:

1. vacuum outlets opening around the circumference of said rollers for engaging the lateral edges of said web in gripping relationship,

2. passages in said rollers in communication with said vacuum outlets;

D. a vacuum pump in communication with said passages;

E. means for rotating said rollers to wrap the lateral edges of said web around said roller to form a hollow cylindrical roll between said rollers;

F. a plunger disposed above said hollow cylindrical roll midway between said opposed rollers which includes:

1. a blunt edged blade, disposed above said rollers with its long axis oriented transversely across said cylindrical roll near its midpoint,

2. said plunger, when extended pushing said blade across the middle of said roll to bend it in the middle and push it downwardly;

G. a pair of driven creasing rollers below said roll and disposed so that their long axes are parallel to the long axis of said blade and which are designed to grab the leading edge of said bent cylindrical roll at the point of the bend in creasing engagement and to flatten both halves of said cylindrical roll together and drive same through said rollers to complete the fold.

2. A material folding apparatus, as defined in claim 1, the further combination therewith of:

A. tensioning means for maintaining tension on said web as it wraps multiple layers around said rollers.

3. A material folding apparatus, as defined in claim 2, in which the web is a tube of plastic material and the tensioning means is a bag forming apparatus, which includes a severing member to sever the web and release the tension onsaid web.

4. A material folding apparatus, as defined in claim 1, in which:

A. said frame reciprocates toward and away from said web severing apparatus,

v B. the further combination therewith of means for reciprocatingsaid frame in forward and backward strokes.

5. A material folding apparatus, as defined in claim 4, the further combination therewith of control means operative to correlate the severing of said web as the forward reciprocating stroke of said frame nears its end.

6. A material folding apparatus, as defined in claim 1, the further combination therewith of a brake to brake the rotation ofsaid pickup rollers.

7. A material folding apparatus, as defined in claim 6, the further combination therewith of a control means to actuate said brake an instant after the web is severed.

8. A material folding apparatus, as defined in claim 1, the further combination therewith of a vacuum cutoff valve and a control means to close said valve to cut off vacuum to said vacuum outlets of said rollers as said plunger is extended and said blade bends the middle of said roll.

9. A material folding apparatus, as defined in claim 1, the further combination of fluid evacuation passages in said pickup rollers to allow air to escape as said blade strokes said roll.

10. A method of folding lengths of material which includes:

A. feeding a web of material onto a pair of spaced and axially opposed pickup rollers;

B. engaging the lateral edges of said web of material on said rollers and wrapping said web around said rollers to form a hollow cylindrical roll;

C. bending said roll in half in a direction perpendicular to the axis of said rollers:

D. disengaging the ends of said roll from said pickup I rollers:

E. pressing both halves of said cylindrical roll together so as to flatten the bent roll and flattening each half of said roll in creasing relation.

6 1]. A method of folding lengths of material, as B. releasing the vacuum simultaneously with bending defined in claim 10, of said roll so as to release the roll from said A. the further step of severing the material in proxpickup rollers.

imity to said roll to separate it from said web. 16. A method of folding lengths of material, as 12. A method of folding lengths of material, as 5 defined in claim 10, in which the steps of bending said defined in claim 11, the further step of: roll include:

A. braking the pickup rollers to a sto an in t nt A. striking the roll transversely at about its midpoint after said web is severed. with a blunt edged blade and pushing it 13. A method of folding lengths of material, as downwardly; defined in claim 10, 10 B. engaging the leading edge of said roll at the point A. the step of maintaining tension on said web as suc- 0f the bend with creasing rollers; and

cessive layers of id material are wrapped on d C. driving the material through said rollers so as to rollers; and press the halves of the roll together and to flatten B. the further step of severing the material in prox each half of the in creasing relationimity to said roll to separate it from said web, and A method of folding lengths of material, as to release tension on said roll. defined in Claim 16, 14. A method of folding lengths of material, as the improvement of evacuating w from t 11ndd fi d i claim 10 in which the step f wrapping Said dle of said roll as the blunt edge blade strikes the web around said pickup rollers includes: midpolm of 531d A rotatively driving Said pickup rollers 20 18. A method of foldlng lengths of material, as

15. A method of folding lengths of material, as defined in claim d fi d in claim 10 which comprises the steps of: A. the further step of evacuatlng alr from the middle applying vacuum to the peripheral Surface of Said of said roll as the roll is bent and as the halves of pickup rollers so as to engage the lateral edges of sad are flattened' said web in gripping relation; 

1. A material folding apparatus, for folding lengths of material fed from a web severing apparatus, which comprises: A. a frame, B. a feed portion for feeding said web onto said apparatus; C. a pair of spaced and axially opposed pickup rollers rotatably journaled in said frame and engagable with the lateral edges of said web, each of said rollers including:
 1. vacuum outlets opening around the circumference of said rollers for engaging the lateral edges of said web in gripping relationship,
 2. passages in said rollers in communication with said vacuum outlets; D. a vacuum pump in communication with said passages; E. means for rotating said rollers to wrap the lateral edges of said web around said roller to form a hollow cylindrical roll between said rollers; F. a plunger disposed above said hollow cylindrical roll midway between said opposed rollers which includes:
 1. a blunt edged blade, disposed above said rollers with its long axis oriented transversely across said cylindrical roll near its midpoint,
 2. said plunger, when extended pushing said blade across the middle of said roll to bend it in the middle and push it downwardly; G. a pair of driven creasing rollers below said roll and disposed so that their long axes are parallel to the long axis of said blade and which are designed to grab the leading edge of said bent cylindrical roll at the point of the bend in creasing engagement and to flatten both halves of said cylindrical roll together and drive same through said rollers to complete the fold.
 2. passages in said rollers in communication with said vacuum outlets; D. a vacuum pump in communication with said passages; E. means for rotating said rollers to wrap the lateral edges of said web around said roller to form a hollow cylindrical roll between said rollers; F. a plunger disposed above said hollow cylindrical roll midway between said opposed rollers which includes:
 2. said plunger, when extended pushing said blade across the middle of said roll to bend it in the middle and push it downwardly; G. a pair of driven creasing rollers below said roll and disposed so that their long axes are parallel to the long axis of said blade and which are designed to grab the leading edge of said bent cylindrical roll at the point of the bend in creasing engagement and to flatten both halves of said cylindrical roll together and drive same through said rollers to complete the fold.
 2. A material folding apparatus, as defined in claim 1, the further combination therewith of: A. tensioning means for maintaining tension on said web as it wraps multiple layers around said rollers.
 3. A material folding apparatus, as defined in claim 2, in which the web is a tube of plastic material and the tensioning means is a bag forming apparatus, which includes a severing member to sever the web and release the tension on said web.
 4. A material folding apparatus, as defined in claim 1, in which: A. said frame reciprocates toward and away from said web severing apparatus, B. the further combination therewith of means for reciprocating said frame in forward and backward strokes.
 5. A material folding apparatus, as defined in claim 4, the further combination therewith of control means operative to correlate the severing of said web as the forward reciprocating stroke of said frame nears its end.
 6. A material folding apparatus, as defined in claim 1, the further combination theRewith of a brake to brake the rotation of said pickup rollers.
 7. A material folding apparatus, as defined in claim 6, the further combination therewith of a control means to actuate said brake an instant after the web is severed.
 8. A material folding apparatus, as defined in claim 1, the further combination therewith of a vacuum cutoff valve and a control means to close said valve to cut off vacuum to said vacuum outlets of said rollers as said plunger is extended and said blade bends the middle of said roll.
 9. A material folding apparatus, as defined in claim 1, the further combination of fluid evacuation passages in said pickup rollers to allow air to escape as said blade strokes said roll.
 10. A method of folding lengths of material which includes: A. feeding a web of material onto a pair of spaced and axially opposed pickup rollers; B. engaging the lateral edges of said web of material on said rollers and wrapping said web around said rollers to form a hollow cylindrical roll; C. bending said roll in half in a direction perpendicular to the axis of said rollers: D. disengaging the ends of said roll from said pickup rollers: E. pressing both halves of said cylindrical roll together so as to flatten the bent roll and flattening each half of said roll in creasing relation.
 11. A method of folding lengths of material, as defined in claim 10, A. the further step of severing the material in proximity to said roll to separate it from said web.
 12. A method of folding lengths of material, as defined in claim 11, the further step of: A. braking the pickup rollers to a stop an instant after said web is severed.
 13. A method of folding lengths of material, as defined in claim 10, A. the step of maintaining tension on said web as successive layers of said material are wrapped on said rollers; and B. the further step of severing the material in proximity to said roll to separate it from said web, and to release tension on said roll.
 14. A method of folding lengths of material, as defined in claim 10, in which the step of wrapping said web around said pickup rollers includes: A. rotatively driving said pickup rollers.
 15. A method of folding lengths of material, as defined in claim 10, which comprises the steps of: A. applying vacuum to the peripheral surface of said pickup rollers so as to engage the lateral edges of said web in gripping relation; B. releasing the vacuum simultaneously with bending of said roll so as to release the roll from said pickup rollers.
 16. A method of folding lengths of material, as defined in claim 10, in which the steps of bending said roll include: A. striking the roll transversely at about its midpoint with a blunt edged blade and pushing it downwardly; B. engaging the leading edge of said roll at the point of the bend with creasing rollers; and C. driving the material through said rollers so as to press the halves of the roll together and to flatten each half of the roll in creasing relation.
 17. A method of folding lengths of material, as defined in claim 16, A. the improvement of evacuating air from the middle of said roll as the blunt edge blade strikes the midpoint of said roll.
 18. A method of folding lengths of material, as defined in claim 10, A. the further step of evacuating air from the middle of said roll as the roll is bent and as the halves of said roll are flattened. 